Want to add a large triangular or pointed window to your house? In Planner 5D, you can combine standard windows with the Magic Cube tool to create custom window designs that follow the shape of your roof.
This technique is especially useful for houses with pitched roofs, attic spaces, and modern gable-style facades.
Let's explore how to create a custom triangular window step by step!
(Written instructions are below)
Step 1. Prepare your house
First, you'll need a room with a pitched roof.
Open your project and switch to 2D mode.
Create a rectangular room or open an existing house project.
Go to Construction → Roofs and select a pitched (gable) roof.
Position the roof above your room, making sure the two slopes meet at the center.
Adjust the roof's dimensions and elevation so its lower edges meet the tops of your walls.
Switch to 3D mode to check how the roof aligns with the house.
The triangular wall section beneath the roof peak is called a gable. This is where we'll create our custom window.
Step 2. Add the lower part of your window
We'll start with a regular rectangular window, which will form the lower section of our custom design.
Switch to 2D mode.
Open Construction → Windows.
Choose a large rectangular window, preferably one with simple frames or mullions.
Place it in the wall beneath the gable.
Adjust its width, height, and elevation to fit your intended design.
For a similar appearance to the tutorial, leave approximately 100–140 cm of wall on each side of the window.
You can also leave a small solid wall section beneath the window rather than extending the glazing all the way to the floor.
Switch to 3D mode and check that the window is centered beneath the roof peak.
Step 3. Prepare the triangular opening
Now we'll create the upper section of the window, following the shape of the gable.
Depending on your house layout, the wall above the rectangular window may block the area where you want the triangular opening.
To prepare it:
Select the wall section above the window.
If necessary, add wall points to separate the section you want to hide from the rest of the wall.
Use the Hide option for the section that should become the upper window opening.
Keep the wall sections on both sides of the opening.
Switch to 3D mode and make sure the upper space is open and aligned with the rectangular window below.
If you need to create custom wall sections around the opening, you can use Magic Cubes to fill the remaining areas.
Important: Hiding a wall section affects that entire segment. Make sure you've separated the correct section before hiding it, so you don't accidentally remove the surrounding wall.
Step 4. Create the triangular window frame
Here's where we'll use the Magic Cube tool to create the custom triangular shape.
Create the vertical frame
Switch to 2D mode.
Open Build → Forms and select Magic Cube.
Resize the cube into a long, thin rectangular strip.
Apply a white material to match your lower window frame.
Position it vertically above the center of the existing window.
Use Levitation to raise it until it connects with the lower frame.
For example, you can start with a frame thickness of approximately 5–10 cm.
Adjust the length until the vertical strip reaches the intended roof peak.
You can duplicate the strip to add additional vertical mullions if your window design requires them.
For more information about creating custom shapes, see How to Use the Magic Cube and Forms on Web.
Create the sloped frame
Now let's make the two upper sides of the triangular window.
Add another Magic Cube.
Resize it into a long, thin strip.
Switch to 3D mode.
Select the strip and enable 3-Axis Rotation.
Tilt it to follow the slope of one side of the roof.
Adjust its length and elevation until it runs from the lower corner of the triangular opening toward the peak.
Duplicate the strip and reverse its slope for the opposite side.
Position both strips so their upper ends meet at the roof peak.
You should now have a pointed frame following the shape of your gable.
For detailed instructions, see How to Use 3-Axis Rotation.
Step 5. Add horizontal and vertical window divisions
To make your triangular window look more realistic, you can add additional frame pieces.
Create a new thin Magic Cube.
Rotate it horizontally.
Position it across the window opening at your preferred height.
Resize it so both ends connect with the surrounding frame.
Duplicate it to create additional horizontal divisions if needed.
You can also duplicate the vertical mullions to divide the window into several sections.
Try to align the upper divisions with the mullions of the rectangular window below.
Tip: Once you're happy with your first frame piece, you can duplicate it instead of creating every piece from scratch. You can also hold Cmd (Mac) or Ctrl (Windows) while clicking multiple pieces to select/group and reposition them together.
Step 6. Fill the wall sections around the window
Once the triangular frame is complete, you may notice empty spaces between the frame and the roof.
Let's close those gaps!
Open Construction → Roofs.
Look for a suitable triangular or wedge-shaped construction element.
Place it beside the triangular window frame.
Adjust its dimensions and position so it fills the area between the window and the roof.
Duplicate or add matching pieces on the opposite side.
For smaller rectangular gaps, you can use Magic Cubes.
Apply the same material to these pieces as the surrounding exterior walls.
Tip: Check the result in 3D after placing each piece. Make sure none of the solid wall elements covers the window opening.
If you've moved the roof aside to access the wall, return it to its original position and check that the infill pieces fit beneath the roof slopes.
Step 7. Add glazing to the upper window
Your triangular window frame is ready, but there's one more important detail.
The rectangular window you added earlier already includes glass. However, the upper triangular section we've created using Magic Cubes is only a decorative frame.
Magic Cubes don't automatically become transparent window glass.
If you want the upper section to appear glazed, you'll need to use a compatible transparent object or material, where supported by your version of Planner 5D.
Make sure the glazing fits behind the frame and doesn't cover the surrounding walls.
If suitable transparent geometry isn't available, you can still use the custom frame to create the appearance of an open triangular window in your 3D design.
Step 8. Customize the window and facade
Now let's finish the appearance of your house.
Select the custom window frame pieces.
Apply the same material or color to all of them.
Adjust the surrounding wall materials to match your facade.
Check that the roof and window frame create a consistent design.
For example, you can combine white window frames, grey vertical wall cladding, and a dark pitched roof for a modern exterior.
Switch to 3D mode and inspect the window from the front and from both sides.
Make sure that:
The triangular frame is centered beneath the roof peak.
Both sloped frame sections meet neatly at the top.
The upper and lower window divisions are aligned.
The surrounding wall pieces don't cover the opening.
All frame pieces use matching materials.
No objects extend through the roof.
If a frame piece appears to float or doesn't align correctly, select it and adjust its Levitation, dimensions, or rotation.